Tuesday, 11 January 2005
Last Updated Tuesday, 11 January 2005
What
May-Hegglin Anomaly (MHA) is a rare inherited bleeding disorder. However, only 25-40% of children with MHA have bleeding tendencies. In MHA, bleeding occurs due to low levels of
platelets.
platelets are tiny particles in the blood that help form clots to stop bleeding. MHA is characterized by giant
platelets and low platelet numbers (thrombocytopenia). Also found in people with MHA are abnormal rod-shaped particles inside the white blood
cells called Dohle bodies. The significance of this is unknown. There is no increased risk of infection. MHA was first described in 1945 by doctors Hegglin and May.
Who
MHA is a very rare disorder. The exact
incidence of MHA is unknown. Only a few hundred cases have been reported.
Signs and Symptoms
Approximately half of the children with MHA have normal platelet counts, while the rest have thrombocytopenia. These children may experience gum/nose bleeding, easy bruising, purpura (purple areas on the skin where superficial bleeding has occurred) and petechia (tiny red spots on the skin that resemble a rash and are usually found on the lower legs or inside the mouth), heavy menstrual bleeding, and excessive bleeding associated with surgical procedures. Fatal bleeding has not been reported. However, children with MHA are at risk for bleeding in the brain after severe head trauma.
Possible Causes
MHA is a hereditary disorder. It is not contagious or preventable. It is caused by a genetic change (
mutation) in a
gene located on
chromosome 22. MHA is inherited in an autosomally dominant manner. This means that a child has to inherit only one mutated version of the
gene to have this disorder. If one parent has the
mutation, there is a 50% chance that each child will inherit the changed
gene. Thus, a family history of bleeding tendencies may be present. Some cases of MHA are not inherited, but are instead the result of a spontaneous
mutation. The genetic
mutation results in defective platelet maturation and ultimately giant
platelets.
Diagnosis
Blood tests show moderately reduced platelet counts and bleeding time is prolonged. Giant
platelets can be identified under a microscope, as can white blood
cells with Dohle bodies.
Treatment
Since most children with MHA do not experience significant bleeding, treatment is usually not required. If severe bleeding occurs, platelet transfusions may be needed. Prior to surgery, children with known MHA must receive a platelet transfusion to prevent bleeding. Steroid therapy and removal of the spleen, which are often done to treat other diseases involving low
platelets numbers, have not been useful.
Prognosis
Most children with MHA live normal lives. Aspirin and other blood thinning medications must be avoided to prevent bleeding. If platelet counts are low or the child is prone to severe bleeding, the child must refrain from contact sports and must wear protective gear, such as helmets, during physical activity.
Connect with other parents
In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease,
please fill out this brief form.
Weblinks
The Platelet Disorder Support Association
http://www.pdsa.org/aboutus.htm
A non-profit corporation providing information and support for people with platelet disorders, including May Hegglin Anomaly.
Genetic Alliance
http://www.geneticalliance.org/
International coalition providing resources, education and networking.
March of Dimes Birth Defects Foundation
http://www.marchofdimes.com
Non-profit organization providing support groups, education, information about research studies, counseling, and family networking.
Google Search for May-Hegglin Anomaly
References and Sources
www.my.webmd.com/hw/health_guide_atoz/nord160.asp
www.whonamedit.com/synd.cfm/113.html
www.emedicine.com/ped/topic1383.htm
